1. Field of the Invention
The present invention relates in general to automatic transmissions and more particularly to an automatic transmission shift control device adapted to prevent shift of gears from P (parking) to other gears unless the brake pedal is fully depressed.
2. Description of the Prior Art
An example of an automatic transmission shift control device of the above described kind is shown in Japanese Utility Model provisional Publication No. 60-185750.
A problem of the prior art shift control device is that the solenoid pin of the solenoid is liable to be deformed to cause malfunction of the shift control device since, if the selector lever in a locked condition is subjected to an operating force for shifting gears, the solenoid pin receives the operating force to resist movement of the selector lever. This problem can be solved by increasing the strength of the solenoid pin so that the solenoid pin is not deformed by such an operating force. However, this causes another problem since the solenoid becomes enlarged which increases the manufacturing cost, weight and design and layout restrictions.
With a view to solving the above problem, an automatic transmission shift control device has been proposed as disclosed in U.S. patent application Ser. No. 214,068 filed on July 1, 1989, issued Dec. 5, 1989 as U.S. Pat. No. 4,884,668 and assigned to the same assignees of this application. This control device is constructed so that a solenoid needs to be kept energized in order to hold the device in a condition of permitting a shift of gears.